Thank you. There's always hope. My case was crazy. I started all this February 2016. I finally sent out my AOS package early November 2016. Didn't even realize I needed to fill out DS260 until January 9. Got a checklist on January 23 for I864 and birth certificate. Thought I was supposed to bring birth certificate to interview. Finally realized, and mailed it in March. Then, found this forum after all this mess. So, there's always hope.
I missed my wife's birth certificate. Mailed it and tracked it. Received March 6. I got cc on March 17. Less than 2 weeks for missing documents for me. There is hope.